I'm in the process of framing my HT build and I am not planning on doing extensive soundproofing. One layer of drywall, no RISC clips or hat channels, no DD/GG, but I *am* going to install a drywall ceiling and also decouple my walls and use a staggered stud arrangement on wall between the HT and the adjacent room. It's not that I don't CARE about soundproofing, but I'm just not able to go all-out with all the extras that many of you guys use for your dedicated HT rooms. So, I'm using good soundproofing practices where I can: solid entry door, decoupled walls, insulation in ceiling and walls, no ceiling can lighting, etc.
That being said, I was originally planning to use 5/8" drywall, but it occurs to me that I might be able to get away with 1/2" drywall instead. Without only one layer of drywall, is the mass-benefit of the 5/8" worth the extra cost and physical effort of installing it? I'm going to do the work myself, so if I can install 50 lb. slabs of 1/2" drywall instead of 70 lb. slabs of 5/8", I'd do it if it made no noticeable difference in soundproofing quality.
I'm not looking for a night-and-day difference, but if it will make a NOTICEABLE difference, then I'd go for the 5/8". Maybe one of you more experienced guys can tell me if the 1/2" drywall would be "just as good" in this particular application.